Researchers at the University of Cambridge have developed a new type of neural implant that combines stem cells and electronics. This could help amputees and people who have lost a limb.
The development of implantable neurotechnology and cell therapy may provide effective treatments for patients with injuries to the peripheral nervous system, the nerves outside the brain and spinal cord. Both attempt to restore function in a paralyzed or amputated limb by bypassing the site of injury and interacting with existing nerve cells, or by replacing damaged cells with new ones.
However, it has its drawbacks. As far as replacement of damaged cells is concerned, transplanted neurons can struggle to establish functional connections. Also, electrodes cannot function effectively without healthy working cells to interact with, usually due to scar tissue that has accumulated at the site of injury. It lacks the ability to work with different types of neurons.
A potential answer to these problems lies in biohybrid devices. It combines human stem cells and bioelectronics to create a more effective neural interface. Now, researchers at the University of Cambridge have done just that, creating a groundbreaking new biohybrid device that can integrate with body tissue.
A key component of this device is induced pluripotent stem cells (iPSCs). These are adult cells (usually skin or blood cells) that can be reprogrammed in the lab to become like embryonic stem cells and grow into other types of cells. Researchers used iPSCs to create muscle cells, the cells that are the building blocks of skeletal muscle. This is the first time that iPSCs have been used in vivo in this way.
iPSCs are arranged in a grid on a microelectrode array (MEA) so that they can be attached to nerve terminals. This generated a layer of muscle cells between the device’s electrodes and the living tissue. The researchers then tested the biohybrid device by implanting it in rats. They attached the cell-coated side of the device to severed ulnar and median nerves in the front legs of rats. These nerves were chosen because they mimic human upper extremity nerve injury and concomitant loss of fine motor and sensory functions.
Compared to a control group, the researchers found that the device integrated with the rat’s body and prevented the formation of scar tissue. This is the first time the cells survived this kind of extended experiment.
Co-author of the study, Dr. Damiano Barone, said: “We can teach them how to behave and check them through experiments. By placing cells between the electronic device and the living body, the body does not recognize the electrodes, only the cells.” Therefore, no scar tissue is produced.”
Four weeks later, researchers tested the transplanted nerves and found that they behaved like normal nerves. This indicates healthy neurophysiology. Although the rats were unable to regain movement in their paralyzed limbs, the device was able to detect signals sent from the brain that controlled movement.
The new device could regenerate neurons caused by injury or amputation and assist amputees in trying to rebuild damage to their neural circuits.
“For example, if someone has an arm or leg amputated, even though the physical limb is gone, all the signals in the nervous system are still there,” Barone said. The challenge in restoring function is extracting information from the nerve and delivering it to the limb to restore function.”
The researchers say their device could overcome this problem by interacting directly with the neurons that control motor functions.
“This interface has the potential to revolutionize the way we interact with technology,” said co-author Amy Rochford. “By combining living human cells with bioelectronic materials, we have created a system that can communicate with the brain in a more natural and intuitive way.”
This device has advantages over standard non-stem cell neural implants. Its small size means it is implantable using keyhole surgery, and using lab-produced stem cells makes it highly scalable.
“This technology represents an exciting new approach to neural implants and we hope it will unlock new treatments for patients in need,” said study co-lead author Dr. Alejandro Carnicer-Lombarte. says.
Although the device requires further research and extensive testing before it can be used in humans, it represents a promising development of neural implants. Researchers are working to optimize the device and improve its scalability.
The study was published in a journal scientific progress.
Source: University of Cambridge
